1. Field of the Invention
The invention relates to a semiconductor device having stacked semiconductor components and a method for producing a semiconductor device having stacked semiconductor components.
2. Description of the Related Art
Although applicable, in principle, to any desired integrated circuits, the present invention and the problems on which it is based will be explained with reference to integrated memory circuits.
In memory circuit technology, preference is given to arrangements of memory components which allow extremely short rewirings between the individual components. This is expedient in order to achieve short signal propagation times between the memory components and, in this manner, to enable short latencies and a high data transfer rate. The power losses in the rewirings as well as the capacitance of the rewiring are also reduced.
As the integration density of present-day semiconductor technology increases, a more and more compact design in one plane is enabled. The integration density can be increased further by stacking the memory components one above the other in a plurality of planes. One common method is to populate circuit boards on two sides. This makes it possible for at least two semiconductor components to be arranged one above the other. A plurality of such populated circuit boards may also be stacked and vertically contact-connected using cables or plug connections. However, this results in high costs for contact-connecting and installing the circuit boards. It is not possible to considerably reduce the wiring lengths and the parasitic capacitances either.
Other methods provide for the memory components to be placed directly on top of one another. In one arrangement, two semiconductor housings (TSOP housings) are stacked on top of one another and the external contact connections (pins) are soldered to one another. Another variant provides for two unhoused semiconductor components (dies) to be placed on top of one another and for a respective contact of the two unhoused semiconductor components to be internally wired (bonded) internally to the same external contact of a housing. However, the structural height of such a stack is too great for many applications and, in addition, only a few (two to three) components can be stacked. The rewirings also have a capacitance and inductance which are too high, on account of their length and the large number of contact connections, for such a stack to be suitable for radiofrequency applications. Moreover, the impedance of the rewirings is not matched.
Another device places a semiconductor component in a prefabricated housing. This housing has external contacts toward its underside and external contacts toward its top side, which contacts are respectively connected to one another. During the production method, the contacts are internally wired to an unhoused semiconductor component. A plurality of semiconductor components can thus be vertically integrated by stacking the housings.
The disadvantage is that the prefabricated housings must be made and stocked in accordance with the functionality of the semiconductor components. Given changing dimensions of the semiconductor components on account of an increased integration density and/or extended range of functions, new housing shapes with new internal dimensions are required. In addition, their structural height is too great for many applications which is why only a few devices can be stacked. The internal rewiring also has an inductance and capacitance which are too high for the device to be suitable for radiofrequency applications.